Eczema

Question 1

Define eczema

Answer 1

Pruritic papulovesicular skin reaction

Question 2

What are the causes/risk factors of eczema?

Answer 2

Atopic:
• Family history
• Atopy – allergic rhinitis, asthma

Contact:
• Type IV delayed hypersensitivity
reaction to allergen e.g. nickel,
perfumes, latex (allergic)
• Prolonged skin contact with celldamaging irritant e.g. ammonia
in nappy rash (irritant)

Seborrhoeic:
• Pityrosporum yeast

Discoid:
• Reaction to bacterial antigen
• Chronic stress

Dyshidrotic:
• Unknown aetiology
• Linked to food allergens and dust mites

Herpetiformis:
• Specific feature of coeliac disease. The severity of the rash is related to the amount of gluten ingested.

Question 3

What are the symptoms of eczema?

Answer 3

• Pruritus
• Xerosis (dry skin)
• Heat
• Tenderness

Contact:
• swelling and blistering (acute)
• hyperpigmentation, fissuring and scaling (chronic)

Discoid:
• round oval area affected

Dyshidrotic:
• on palms, soles of feet and sides of fingers
• skin id dry and ‘rough’

Seborrhoeic:
• itchiness and inflammation of the scalp, beard area or neck
• most common presentation is during puberty in men. Also associated with Parkinson’s disease in the elderly.

Herpetiformis:
• rash on extensor surface
• diagnosed CD/history of abdominal pain

Question 4

What are the signs of eczema?

Answer 4

Atopic
• Dry skin with erythema and scaling, and often with papules or vesicles
• In infants, the cheeks and forehead are preferentially affected
• In older children, it occurs in the body flexures.

Contact dermatitis:
• The eruption is often clearly delineated with sharp borders and confined to the areas where the irritant or allergen has come into contact with the skin.

Discoid Eczema:
• Disk/ oval shaped –similar in appearance to contact dermatitis.

Dyshidrotic:
• Blisters (1-2mm) filled with watery fluid on the palms, soles and the edges of fingers.

Seborrheic:
• Erythematous, circumscribed and scaly patches on the scalp, face or chest

Herpetiformis
• Small papules or vesicles that usually look like red bumps or blisters. They vary in size from very small up to 1 cm. They are distributed symmetrically on extensor surfaces.

Question 5

What investigations are carried out for eczema?

Answer 5

• Atopic Eczema - clinical Diagnosis.
- Allergen Testing
- IgE Levels –Elevated.
• Contact Eczema - skin patch testing: Disc containing postulated allergen is diluted and applied to back for 48 hours.
- Positive if allergen induces a red raised lesion.
• Discoid Eczema - skin patch testing may be useful.
• Dyshidrotic - clinical Diagnosis. Could also do a skin biopsy.
• Seborrheic - clinical Diagnosis. Skin biopsy is rarely needed.
• Herpetiformis - clinical Diagnosis. Investigations for coeliac if not yet diagnosed.